The Black caiman is the largest predator in the Amazon basin measuring 3 to 4m (9 –12 ft) in length, with old males growing larger than 5m (15 ft). It is the third largest crocodilian in South America behind the American Crocodile and Orinoco Crocodile.
At the end of the dry season, females build a nest of soil and vegetation abd lay up to 60 eggs at the beginning of the wet season when newly-flooded marshes provide ideal habitat for the juveniles. Unguarded clutches are quickly devoured by a wide range of animals. As with other crocodilians, caimans frequently move their young in their mouths, creating a mistaken impression that they eat their young. Mothers will assist chirping, unhatched young to break out of the leathery eggs by delicately breaking the eggs between her teeth. The female only breeds once every 2 to 3 years.